# Relationship history for MSHA mine 2300875

Current hierarchy: **Martin Marietta Materials Inc → Hunt Martin Materials L.L.C. → Blue Mound Quarry**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **operator_operates_mine:** Green Quarries Inc → Blue Mound Quarry; 1950-01-01 to 2000-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Green Quarries Inc → Blue Mound Quarry; 1950-01-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Green Quarries Inc → Green Quarries Inc; 1950-01-01 to 2000-05-31; source msha-controller-operator-history
- **controller_controls_mine:** Hunt Midwest Enterprises → Blue Mound Quarry; 1985-06-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hunt Midwest Mining Inc → Blue Mound Quarry; 2000-06-01 to 2003-09-09; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Midwest Enterprises → Hunt Midwest Mining Inc; 2000-06-01 to 2003-09-09; source msha-controller-operator-history
- **controller_controls_mine:** Hunt Midwest Enterprises → Blue Mound Quarry; 2002-01-15 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Hunt Midwest Mining Green Quarries  Inc → Blue Mound Quarry; 2003-09-10 to 2005-02-27; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Midwest Enterprises → Hunt Midwest Mining Green Quarries  Inc; 2003-09-10 to 2005-02-27; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc et al → Blue Mound Quarry; 2005-02-01 to 2014-04-02; source msha-controller-operator-history
- **operator_operates_mine:** Hunt Martin Materials L.L.C. → Blue Mound Quarry; 2005-02-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc et al → Hunt Martin Materials L.L.C.; 2005-02-28 to 2014-04-02; source msha-controller-operator-history
- **controller_controls_operator:** Hunt Midwest Enterprises et al → Hunt Martin Materials L.L.C.; 2005-02-28 to 2014-04-02; source msha-controller-operator-history
- **controller_controls_mine:** Martin Marietta Materials Inc → Blue Mound Quarry; 2014-04-03 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Hunt Martin Materials L.L.C.; 2014-04-03 to current/open; source msha-controller-operator-history